High frequency supply for an x-ray tube

Abstract

A high-frequency supply for use with an x-ray tube having a central metallic tap includes two inverse rectifiers each having a high-voltage transformers, forming two series-connected high-voltage rectifiers. The tap of the x-ray tube is electrically connected between the two high-voltage rectifiers. Each inverse rectifier has a capacitor associated therewith, with the inverse rectifier connected at the cathode side of the x-ray tube having a capacitor with a higher capacitance than the inverse rectifier connected at the anode side of the x-ray tube. Current flowing in the line connected to the tap between the two high-voltage rectifiers is thus compensated, so that a shift in the center of the high-voltage is avoided.

We claim as our invention: 
     
       1. A high-voltage supply circuit for feeding an x-ray tube having an anode side and a cathode side, said circuit comprising: first and second resonant circuit inverse rectifiers connectable to a d.c. voltage source;   first and second high-voltage transformers respectively fed by said first and second resonant circuit inverse rectifiers;   first and second high-voltage rectifiers connected in series and respectively connectable to the anode side and to the cathode side of an x-ray tube, said first and second high-voltage rectifiers being respectively fed by said first and second high-voltage transformers; and   said first and second resonant circuit inverse rectifiers each having a resonant circuit impedance, and said respective resonant circuit impedances of said first and second resonant circuit inverse rectifiers being different.   
     
     
       2. A high-frequency voltage supply circuit as claimed in claim 1 wherein said resonant circuit impedances are respectively different capacitances, and wherein said second resonant circuit inverse rectifier, connectable at said cathode side of said x-ray tube, has a larger capacitance than said first resonant circuit inverse rectifier, connectable at said anode side of said x-ray tube. 
     
     
       3. A high-frequency voltage supply circuit as claimed in claim 2, further comprising: means in at least one of said first and second resonant circuit inverse rectifiers for switching the magnitude of said capacitance.   
     
     
       4. A high-frequency voltage supply circuit as claimed in claim 3 wherein said at least one resonant circuit inverse rectifier includes two capacitors, and wherein said means for switching is connected to said two capacitors for selectively connecting one or both of said two capacitors in said at least one resonant circuit inverse rectifier.